Sometimes when driving out of the city, there are landslides in the mountains after it rains, or rocks fall, which can be very difficult and dangerous. Sometimes this creates huge traffic jams and requires new construction. It also increases the risk of accidents happening.
Because I work in the College of Engineering, I know some professors in Civil Engineering who work with soil. They are working on projects to build tunnels in the mountains to help avoid landslides and their associated danger and prevent accidents surrounding them on the roads.